A solid-state aluminum electrolytic capacitor based on Ti3SiC2 doping and a preparation method thereof

Abstract

A kind of solid-state aluminum electrolytic capacitor based on Ti3SiC2 doping, including shell and core package, core package is sealed and arranged in shell;The core package includes anode foil, electrolytic paper and cathode foil, electrolytic paper is arranged between anode foil and cathode foil, and high molecular conductive polymer film is formed between anode foil and cathode foil, Ti3SiC2 is doped in high molecular conductive polymer film.In the present application, the internal resistance of solid-state aluminum electrolytic capacitor can be effectively reduced after using Ti3SiC2 in solid-state electrolyte;In the present application, the cycle performance of solid-state aluminum electrolytic capacitor is improved due to the supporting effect of Ti3SiC2 on high molecular conductive polymer after Ti3SiC2 doping.

Description

TECHNICAL FIELD

[0001] The present application relates to a solid-state aluminum electrolytic capacitor, in particular to a solid-state aluminum electrolytic capacitor based on Ti3SiC2 doping with small internal resistance and a preparation method thereof. BACKGROUND

[0002] At present, solid-state capacitors have good application prospects due to their good growth. The solid-state capacitor uses high-molecular material with high conductivity and good thermal stability to replace the traditional electrolyte. Therefore, compared with ordinary liquid aluminum electrolytic capacitors, it has high reliability, long service life, high frequency, low impedance, large ripple current resistance and other characteristics. Therefore, one solid-state capacitor can replace 2-3 ordinary aluminum electrolytic capacitors, and can overcome the leakage defect of liquid aluminum electrolytic capacitors. Therefore, it has wide application prospects in the integration and miniaturization of electronic products. At present, it has been applied in the fields of notebook computers, LCD TVs, 3D displays, game consoles and the like. With the rise of 5G network and electronic information industry and the upgrading of consumption structure, especially with the gradual decline of the price of its core raw materials, the application range of solid-state capacitors will continue to expand in the future, and the market demand will also increase rapidly.

[0003] However, with the development of the market, the requirements for solid-state aluminum electrolytic capacitors are also getting higher and higher, but the internal resistance and cycle performance of the current solid-state aluminum electrolytic capacitors still cannot fully meet the market demand. SUMMARY

[0004] The technical problem to be solved by the present application is to overcome the shortcomings of the prior art and provide a solid-state aluminum electrolytic capacitor based on Ti3SiC2 doping with small internal resistance and good cycle performance and a preparation method thereof.

[0005] To solve the above technical problems, the technical solution provided by the present application is as follows: a solid-state aluminum electrolytic capacitor based on Ti3SiC2 doping, comprising a shell and a core package, the core package is sealed in the shell; characterized in that: the core package comprises an anode foil, an electrolytic paper and a cathode foil, the electrolytic paper is arranged between the anode foil and the cathode foil, a high-molecular conductive polymer film is formed between the anode foil and the cathode foil, and Ti3SiC2 is doped in the high-molecular conductive polymer film.

[0006] The solid-state aluminum electrolytic capacitor based on Ti3SiC2 doping described above, preferably, the weight ratio of Ti3SiC2 to the monomer of the high-molecular conductive polymer is 1:40-1:10.

[0007] The solid-state aluminum electrolytic capacitor based on Ti3SiC2 doping described above, preferably, the high-molecular conductive polymer is a PEDOT film, a polyaniline film or a polypyrrole film.

[0008] Preferably, in the above-mentioned solid aluminum electrolytic capacitor based on Ti3SiC2 doping, the core package is a stacked core package, a polymer conductive film is formed on the surface of the anode foil, and a Ti3SiC2 doped polymer conductive film is formed on the cathode foil.

[0009] A method for preparing a solid aluminum electrolytic capacitor based on Ti3SiC2 doping includes the following steps;

[0010] 1) Ti3SiC2 powder is added to the conductive polymer monomer solution to form a uniform impregnation solution; the weight ratio of Ti3SiC2 to conductive polymer monomer is 1:40-1:10;

[0011] 2) The core is impregnated with the impregnation solution formed in step 1), and then dried;

[0012] 3) The core from step 2) will be impregnated with an oxidizing agent;

[0013] 4) The core package impregnated with oxidant is subjected to polymerization reaction; the polymerization temperature is 50-120℃;

[0014] 5) Assembly;

[0015] 6) Aging.

[0016] In the above-mentioned method for preparing a solid aluminum electrolytic capacitor based on Ti3SiC2 doping, preferably, the temperature is increased sequentially from 50-70°C during the polymerization reaction; the temperature increase is not more than 50°C each time, and the temperature is held for 30-90 minutes after each temperature increase.

[0017] In the above-mentioned method for preparing a solid aluminum electrolytic capacitor based on Ti3SiC2 doping, preferably, the solvent of the impregnation solution in step 1) includes one or more of deionized water, ethanol, ethylene glycol, propylene glycol, and glycerol, and the concentration of the conductive polymer monomer in the impregnation solution is 1-10%.

[0018] A method for fabricating a Ti3SiC2-doped solid aluminum electrolytic capacitor includes the following steps:

[0019] 1) Ti3SiC2 powder is added to the conductive polymer monomer solution to form a uniform coating liquid; the weight ratio of Ti3SiC2 to conductive polymer monomer is 1:40-1:10.

[0020] 2) Apply the coating solution from step 1) evenly onto the cathode foil;

[0021] 3) Coat the cathode foil from step 2) evenly with the oxidant;

[0022] 4) The cathode foil from step 3) is subjected to a polymerization reaction;

[0023] 5) The cathode foil, diaphragm, and anode foil formed in step 4) are stacked sequentially to form a stacked core package;

[0024] 6) A conductive polymer film is formed in the anode foil in the stacked core package formed in step 5) and in the cathode foil formed in step 4);

[0025] 7) Assemble.

[0026] In the above-mentioned method for preparing a solid aluminum electrolytic capacitor based on Ti3SiC2 doping, preferably, the temperature is increased sequentially from 50-70°C during the polymerization reaction; the temperature increase is not more than 50°C each time, and the temperature is held for 30-90 minutes after each temperature increase.

[0027] In the above-mentioned method for preparing a solid aluminum electrolytic capacitor based on Ti3SiC2 doping, preferably, step 6) involves directly impregnating a dispersion of a conductive polymer and then drying it; the concentration of the conductive polymer in the dispersion is 1-5%.

[0028] The above-described method for preparing a solid aluminum electrolytic capacitor based on Ti3SiC2 doping, preferably, includes the following steps in step 6):

[0029] The laminated core formed in step 5) is impregnated with a monomer solution of a conductive polymer and then dried.

[0030] Steps The core contains an oxidizing agent; then a polymerization reaction is carried out.

[0031] Compared with the prior art, the advantages of the present invention are as follows: In the present invention, the use of Ti3SiC2 in the solid electrolyte can effectively reduce the internal resistance of the solid aluminum electrolytic capacitor; In the present invention, the solid electrolyte doped with Ti3SiC2 improves the cycle performance of the solid aluminum electrolytic capacitor due to the supporting effect of Ti3SiC2 on the conductive polymer. Detailed Implementation

[0032] To facilitate understanding of the present invention, the present invention will be described more fully and in detail below with reference to preferred embodiments, but the scope of protection of the present invention is not limited to the following specific embodiments.

[0033] It should be noted that when a component is described as being "fixed to, attached to, connected to or connected to" another component, it can be directly fixed to, attached to, connected to or connected to the other component, or it can be indirectly fixed to, attached to, connected to or connected to the other component through other intermediate connectors.

[0034] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.

[0035] Example 1

[0036] A Ti3SiC2-doped solid aluminum electrolytic capacitor includes a casing and a core, the core being sealed inside the casing by a rubber stopper. In this embodiment, the core is formed by winding an anode foil, electrolytic paper, and a cathode foil, with the electrolytic paper disposed between the anode and cathode foils. A Ti3SiC2-doped PEDOT film is formed between the anode and cathode foils. In this embodiment, the conductive polymer is PEDOT, and the weight ratio of Ti3SiC2 to the monomer of the conductive polymer is 1:40-1:10.

[0037] In this embodiment, doping PEDOT with Ti3SiC2 can effectively reduce the internal resistance of the conductive polymer. At the same time, during the charge-discharge cycle of the solid aluminum electrolytic capacitor, Ti3SiC2 supports the expansion and contraction of PEDOT, thereby effectively improving the cycle performance of the solid aluminum electrolytic capacitor.

[0038] This embodiment also provides a method for preparing a solid aluminum electrolytic capacitor based on Ti3SiC2 doping, characterized by including the following steps;

[0039] 1) Ti3SiC2 powder is added to EDOT solution to form a uniform impregnation solution; the weight ratio of Ti3SiC2 to EDOT is 3:80; the weight ratio of Ti3SiC2 to EDOT can be set between 1:40 and 1:10 depending on the specific situation.

[0040] 2) The core is impregnated with the impregnation solution formed in step 1), and then dried;

[0041] 3) The core containing the oxidizing agent ferric p-toluenesulfonate after completing step 2) is impregnated;

[0042] 4) The core package impregnated with oxidant is subjected to a polymerization reaction;

[0043] 5) Assembly;

[0044] 6) Aging.

[0045] In this embodiment, the polymerization reaction was carried out in the following order: holding at 50°C for 60 min, holding at 80°C for 90 min, holding at 100°C for 60 min, and holding at 120°C for 60 min.

[0046] In other embodiments, to accelerate the impregnation rate of the PEDOT monomer EDOT, EDOT can be dispersed in a solvent to form an impregnation solution. The solvent includes one or more of deionized water, ethanol, ethylene glycol, propylene glycol, glycerol, etc.; the weight concentration of EDOT in the impregnation solution is 8%; the weight concentration of EDOT in the impregnation solution can be set according to specific circumstances, generally between 1% and 10%.

[0047] In this embodiment, the anode foil is a chemically formed foil. The specific method of chemical formation is as follows: 40 volumes of ammonium adipate solution are placed in a 100-volume water bath and heated to a constant temperature of 65°C. A voltage of 9 V is provided by a voltage regulator. A platinum electrode is used as the auxiliary electrode, and the anode is used as the working electrode. Chemical formation is carried out for 30 minutes. After chemical formation, the anode is washed with pure water and then dried in a drying oven at 120-160°C for 2-3 hours. In this embodiment, ammonium adipate solution can be replaced with ammonium acetate.

[0048] In this embodiment, the surface of Ti3SiC2 is oxygen-free. However, in polar solvents, hydroxyl groups readily form on the Ti3SiC2 surface. These hydroxyl groups form π-π bonds with EDOT during EDOT polymerization. In this embodiment, Ti3SiC2 has a layered structure and very high conductivity. A large conductive network is formed by PEDOT in the solid electrolyte of the aluminum electrolytic capacitor, and coupling between Ti3SiC2 and PEDOT effectively reduces the resistance of the solid electrolyte. The average capacitance of the 20 solid aluminum electrolytic capacitors in this embodiment is 964 μF, and the ESR value reaches 12.8 mΩ. Simultaneously, during the charge-discharge cycles of the solid aluminum electrolytic capacitors, Ti3SiC2 provides support for PEDOT, thereby improving the cycle performance of the solid aluminum electrolytic capacitors. In this application, after 2000 charge-discharge cycles at 42V and 20A, the capacitance retention of the solid aluminum electrolytic capacitors reaches 91.3%.

[0049] Comparative Example 1

[0050] In Comparative Example 1, the PEDOT film formed between the anode foil and the cathode foil was not doped with Ti3SiC2, and everything else was the same as in Example 1. The solid aluminum electrolytic capacitor produced in Comparative Example 1 had a capacitance of 971 μF and an internal resistance of 16.3 mΩ. After 2000 charge-discharge cycles at 42V and 20A, the capacitance retention of the solid aluminum electrolytic capacitor could reach 88.6%.

[0051] Example 2

[0052] In this embodiment, the solid aluminum electrolytic capacitor is a square aluminum electrolytic capacitor with a stacked core. A PEDOT film is formed on the surface of the anode foil, and a Ti3SiC2-doped PEDOT film is formed on the cathode foil.

[0053] The method for preparing a Ti3SiC2-doped solid aluminum electrolytic capacitor in this embodiment includes the following steps:

[0054] 1) Ti3SiC2 powder is added to EDOT solution to form a uniform coating solution; the weight ratio of Ti3SiC2 to EDOT is 1:40-1:10.

[0055] 2) Apply the coating solution from step 1) evenly onto the cathode foil;

[0056] 3) Coat the cathode foil from step 2) evenly with the oxidant ferric toluenesulfonate solution;

[0057] 4) The cathode foil from step 3) is subjected to a polymerization reaction;

[0058] 5) The cathode foil, diaphragm, and anode foil formed in step 4) are stacked sequentially to form a stacked core package;

[0059] 6) A conductive polymer film is formed in the anode foil in the stacked core package formed in step 5) and in the cathode foil formed in step 4);

[0060] 7) Assemble.

[0061] In this embodiment, step 6) involves directly impregnating a PEDOT dispersion and then drying it; the weight concentration of PEDOT in the PEDOT dispersion is 1-5%. Since the weight concentration of PEDOT in the PEDOT dispersion is 1-5%, its concentration is relatively low, and its viscosity is low, making it easy to penetrate deep into the anode foil on the core package. This can improve the capacitance of the solid aluminum electrolytic capacitor to some extent. However, due to the relatively small amount of PEDOT impregnated, its internal resistance will increase to some extent.

[0062] In this embodiment, a Ti3SiC2-doped PEDOT film is first formed on the cathode foil, and then stacked into a core package. The core package is then directly impregnated with a PEDOT dispersion. After drying, a PEDOT film is formed on the surface of the anode foil. This PEDOT film can be well bonded to the Ti3SiC2-doped PEDOT film on the cathode foil without forming a break.

[0063] The solid aluminum electrolytic capacitor in this embodiment has a capacitance of 672μF and an ESR of 6.9mΩ. After 2000 charge-discharge cycles at 42V and 20A, the capacitance retention rate of the solid aluminum electrolytic capacitor can reach 90.2%. The other parts of this embodiment are the same as those in Embodiment 1.

[0064] Comparative Example 2

[0065] In Comparative Example 2, the PEDOT film on the cathode foil was not doped with Ti3SiC2, but otherwise it was the same as in Example 2. The solid aluminum electrolytic capacitor fabricated in Comparative Example 2 had a capacitance of 683 μF and an internal resistance of 8.1 mΩ. After 2000 charge-discharge cycles at 42 V and 20 A, the capacitance retention of the solid aluminum electrolytic capacitor reached 87.3%.

[0066] Example 3

[0067] In this embodiment, step 6) includes the following steps:

[0068] The laminated core formed in step 5) is impregnated with a monomer solution of a conductive polymer and then dried.

[0069] Steps The core contains an oxidizing agent, ferric p-toluenesulfonate; then a polymerization reaction is carried out. The other parts of this embodiment are the same as in Example 2.

Claims

1. A solid-state aluminum electrolytic capacitor based on Ti3SiC2 doping, comprising a shell and a core, wherein the core is sealed within the shell; characterized in that: The core package includes an anode foil, an electrolytic paper, and a cathode foil. The electrolytic paper is disposed between the anode foil and the cathode foil. A high-molecular conductive polymer film is formed between the anode foil and the cathode foil. The high-molecular conductive polymer film is doped with Ti3SiC2. The conductive polymer is a PEDOT film, a polyaniline film, or a polypyrrole film.

2. The solid-state aluminum electrolytic capacitor based on Ti3SiC2 doping according to claim 1, characterized in that: The weight ratio of Ti3SiC2 to the monomer of the conductive polymer is 1:40-1:

10.

3. The solid-state aluminum electrolytic capacitor based on Ti3SiC2 doping according to claim 1, characterized in that: The core package is a stacked core package, with a high molecular conductive polymer film formed on the surface of the anode foil and a Ti3SiC2 doped high molecular conductive polymer film formed on the cathode foil.

4. A method for preparing a solid aluminum electrolytic capacitor based on Ti3SiC2 doping, characterized in that: Includes the following steps; 1) Ti3SiC2 powder is added to the conductive polymer monomer solution to form a uniform impregnation solution; the weight ratio of Ti3SiC2 to conductive polymer monomer is 1:40-1:10; 2) The core is impregnated with the impregnation solution formed in step 1), and then dried; 3) The core from step 2) will be impregnated with an oxidizing agent; 4) The core package impregnated with oxidant is subjected to polymerization reaction; the polymerization temperature is 50-120℃; 5) Assembly; 6) Aging.

5. The method for preparing a solid-state aluminum electrolytic capacitor based on Ti3SiC2 doping according to claim 4, characterized in that: During the polymerization reaction, the temperature is gradually increased from 50-70°C; each increase in temperature does not exceed 50°C, and the temperature is maintained for 30-90 minutes after each increase.

6. The method for preparing a solid-state aluminum electrolytic capacitor based on Ti3SiC2 doping according to claim 4, characterized in that: The solvent of the impregnation solution in step 1) includes one or more of deionized water, ethanol, ethylene glycol, propylene glycol, and glycerin; the weight concentration of EDOT in the impregnation solution is 1-10%.

7. A method for preparing a solid aluminum electrolytic capacitor based on Ti3SiC2 doping, characterized in that: Includes the following steps: 1) Ti3SiC2 powder is added to the conductive polymer monomer solution to form a uniform coating liquid; the weight ratio of Ti3SiC2 to conductive polymer monomer is 1:40-1:

10. 2) Apply the coating solution from step 1) evenly onto the cathode foil; 3) Coat the cathode foil from step 2) evenly with the oxidant; 4) The cathode foil from step 3) is subjected to a polymerization reaction; 5) The cathode foil, diaphragm, and anode foil formed in step 4) are stacked sequentially to form a stacked core package; 6) A conductive polymer film is formed in the anode foil in the stacked core package formed in step 5) and in the cathode foil formed in step 4); 7) Assemble.

8. The method for preparing a solid aluminum electrolytic capacitor based on Ti3SiC2 doping according to claim 7, characterized in that: During the polymerization reaction, the temperature is gradually increased from 50-70°C; each increase in temperature does not exceed 50°C, and the temperature is maintained for 30-90 minutes after each increase.

9. The method for preparing a solid-state aluminum electrolytic capacitor based on Ti3SiC2 doping according to claim 7, characterized in that: The method in step 6) is to directly impregnate a dispersion of conductive polymer and then dry it; the concentration of conductive polymer in the dispersion is 1-5%.

10. The method for preparing a solid-state aluminum electrolytic capacitor based on Ti3SiC2 doping according to claim 7, characterized in that: The method in step 6) includes the following steps: ①The laminated core formed in step 5) is impregnated with a monomer solution of a conductive polymer and then dried; ②Immerse the core from step ① in an oxidizing agent; then carry out the polymerization reaction.